Adsorption of carbon dioxide on hydrotalcite-like compounds of different compositions


The adsorption of carbon dioxide on hydrotalcite-like compounds was investigated. Two different powdered hydrotalcites were used containing the cations nickel and iron. The powdered materials were screened for carbon dioxide adsorption using a thermogravimetric method and it was found that NiMgAl (Sample 1) hydrotalcite has the largest capacity for CO2, adsorbing 1.58 mmol g−1 at 20 °C, and highest rate of adsorption of up to 0.17 mmol g−1 min−1. This represented an increase of 53% in adsorption capacity, compared with NiMgAlFe (Sample 2). In order to improve the rheological behaviour of hydrotalcite paste for extrusion, hydrotalcite powders were combined with boehmite alumina (70:30 and 50:50 ratios of hydrotalcite:boehmite) before extrusion into pellets suitable for use in a fixed bed adsorber. These pellets were then re-crushed and further tested by thermogravimetric methods. The effects of temperature, composition and pre-treatment of the hydrotalcites on the adsorption of carbon dioxide and nitrogen are reported. At 20 °C, the amount of carbon dioxide adsorbed was between 2.0 and 2.5 mmol g−1 for all the hydrotalcite/alumina samples in this study, although this decayed rapidly with increasing temperature. The results are compared with silica gel as a common sorbent reference, and with literature values. Hydrotalcite/alumina samples have thermal stability and a high adsorption capacity for carbon dioxide over a wide range of temperatures. The composition of the hydrotalcite/alumina pellets investigated in this study has less effect upon the adsorption behaviour compared with the non-calcined hydrotalcite powder, thus allowing a wide choice of pellet compositions to be used.

Publication DOI:
Divisions: Engineering & Applied Sciences
Uncontrolled Keywords: adsorption,carbon dioxide,hydrotalcite,mixed oxide,carbon capture,thermogravimetric
Full Text Link: http://pure-oai ... shenbrenner.pdf
Related URLs: https://www.sci ... 2868?via%3Dihub (Publisher URL)
PURE Output Type: Article
Published Date: 2011-09
Accepted Date: 2010-09-30
Submitted Date: 2010-05-13
Authors: Aschenbrenner, Ortrud
McGuire, Paul
Alsamaq, Suzanne
Wang, Jiawei ( 0000-0001-5690-9107)
Supasitmongkol, Somsak
Al-Duri, Bushra
Styring, Peter
Wood, Joseph

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